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See detailEvolution des ressources forestières en Afrique de l’Ouest soudano-sahélienne au cours des 50 dernières années
Ariori, Serge Léopold; Ozer, Pierre ULg

in Geo-Eco-Trop (2005), 29

On the basis of an exhaustive consultation of the literature describing the temporal evolution of land cover in arid, semiarid and dry subhumid regions of West Africa, this study shows that the ... [more ▼]

On the basis of an exhaustive consultation of the literature describing the temporal evolution of land cover in arid, semiarid and dry subhumid regions of West Africa, this study shows that the deforestation trend has been very important during the second half of the 20th century. This trend to deforestation is globally large (2% per year) and is clearly alarming. Although our results differ from FAO's official data, it is demonstrated that those are questionable. In addition, if dense woody formations have been strongly reduced in the study area, our study indicates that degraded woody formations are currently declining. Our results clearly go against the recent conclusions of some authors preaching the idea of a 'greening Sahel'. [less ▲]

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See detailEvolution des résultats électoraux et systèmes partisans de 1830 à nos jours.
Verjans, Pierre ULg; Matagne, Geoffroy ULg

in Reuchamps, Min; Bouhon, Frédéric (Eds.) Les systèmes électoraux de la Belgique (2012)

Le système politique belge, caractérisé par la pilarisation et le consociationnisme jusque dans les années soixante du vingtième siècle, période phare de la démocratie de partis, se transforme ... [more ▼]

Le système politique belge, caractérisé par la pilarisation et le consociationnisme jusque dans les années soixante du vingtième siècle, période phare de la démocratie de partis, se transforme radicalement et évolue vers un système centrifuge repérable tant dans les résultats des élections législatives que dans les constitutions de gouvernement. La démocratie du public à la belge s'adresse à deux publics différents cohabitant au sommet. [less ▲]

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See detailEvolution des structures de sols sous itinéraires techniques contrastés : relation entre courbes de rétention et analyse par microtomographie aux rayons X
Beckers, Eléonore ULg; Roisin, Christian; Léonard, Angélique ULg et al

Poster (2010, November)

Tillage reduction seems to affect porosity distribution, orientation and connectivity. Soil samples were removed from plots under conventional tillage or reduced tillage. Their water retention curves were ... [more ▼]

Tillage reduction seems to affect porosity distribution, orientation and connectivity. Soil samples were removed from plots under conventional tillage or reduced tillage. Their water retention curves were measured, and the characterization of soils porosity was made using x-ray microtomography measurements. Results show differences in the meso as well as in the macroporosity. [less ▲]

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See detailEvolution des structures de sols sous itinéraires techniques contrastés : relations entre courbes de rétention et analyse par microtomographie à rayons X
Beckers, Eléonore ULg; Roisin, Christian; Léonard, Angélique ULg et al

in Milieux Poreux et Transferts Hydriques (2010, November), 56

Tillage reduction seems to affect porosity distribution, orientation and connectivity. Soil samples were removed from plots under conventional tillage or reduced tillage. Their water retention curves were ... [more ▼]

Tillage reduction seems to affect porosity distribution, orientation and connectivity. Soil samples were removed from plots under conventional tillage or reduced tillage. Their water retention curves were measured, and the characterization of soils porosity was made using x-ray microtomography measurements. Results show differences in the meso as well as in the macroporosity. [less ▲]

Detailed reference viewed: 78 (39 ULg)
See detailEvolution des structures spatiales en région liégeoise : désurbanisation ou renouvellement urbain ?
Halleux, Jean-Marie ULg

Conference given outside the academic context (2003)

Detailed reference viewed: 3 (0 ULg)
See detailEvolution des traditions culturelles dans la vallée du moyen Euphrate de la fin du Bronze ancien au début du Bronze moyen
Colonna d'Istria, Laurent ULg

Doctoral thesis (2009)

The valley of the Middle Euphrates, hyphen between South Mesopotamia and Western Syria, was ruled by a šakkanakku lived in Mari (Tell Hariri, Syria) during the end of the third millennium and early second ... [more ▼]

The valley of the Middle Euphrates, hyphen between South Mesopotamia and Western Syria, was ruled by a šakkanakku lived in Mari (Tell Hariri, Syria) during the end of the third millennium and early second millennium. This time period named "šakkanakku-period" is particularly studied since twenty years An overview of archaeological and historical data from the Middle Euphrates valley during the time of šakkanakku suggest that the kingdom of Mari during that time has established itself as a power independent and prosperous until the 19th century (end of the time of šakkanakku) where data are less explicit historically. The new text data from Mari, and Terqa (north of Mari), of the most dated from the end of šakkanakku-period, shows continuance and ruptures between the end of šakkanakku-period and the next period ("Amorite-period"). This continuance and ruptures are examined in several areas such as language, "scribal tradition" or in the legal tradition. The dialect of this text (19th century) shows that linguistic tradition is deeply rooted in the universe Syria. After the advent of the Amorite Yahdun-Lim who ended the time of the šakkanakku the Syrian characteristics in the dialect remains present, but it is less important because a reform of writing modeled on southern Mesopotamia (Iraq current), probably due to the preponderance of political Ešnunna during the end of the 19th century. Finally, this new text has also allowed dealing the historical interaction of the last šakkanakku Mari with condottieri Amorite whose father Yahdun-Lim in the 19th century. [less ▲]

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See detailÉvolution des traits d’histoire de vie lors des invasions végétales
Monty, Arnaud ULg; Mahy, Grégory ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2009), 13(3), 449-458

Les invasions par les plantes, malgré les problèmes qu’elles engendrent, sont des opportunités d’étude des phénomènes évolutifs rapides. Dans cet article sont présentés les principaux changements ... [more ▼]

Les invasions par les plantes, malgré les problèmes qu’elles engendrent, sont des opportunités d’étude des phénomènes évolutifs rapides. Dans cet article sont présentés les principaux changements évolutifs d’histoire de vie accompagnant les invasions végétales. Ceux-ci peuvent avoir lieu lors des différentes phases de l’invasion que sont l’introduction, la naturalisation et l’expansion proprement dite. Leur étude s’articule généralement en deux approches : les comparaisons entre populations de l’aire d’indigénat et de l’aire d’invasion d’une part, et d’autre part, les études de la différenciation au sein de l’aire d’invasion. [less ▲]

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See detailEvolution diurne des profils thermiques inversifs les plus courants observés le long de la tour du Bol d'Air au SSW de Liège
Grilli-Delrez, A.; Erpicum, Michel ULg

in Bulletin de la Société Géographique de Liège (1984), 20

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See detailEvolution du bilan d'approvisionnement en céréales de la Belgique de 1970/71 à 2003/04
Burny, Philippe ULg; Matendo, Sadrac; Duquesne, Brigitte ULg

in CRA-w; FUSAGx (Eds.) Livre blanc Céréales-Gembloux, édition février 2006 "Fumure et protection phytosanitaire des céréales" (2006)

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See detailÉvolution du bilan de masse de surface Antarctique par régionalisation physique et conséquences sur les variations du niveau des mers
Agosta, Cécile ULg

Doctoral thesis (2012)

The Antarctic surface mass balance (SMB, i.e. the snow accumulation from which we sub- tract ablation by sublimation, run-off or erosion) is a major yet poorly known contribution to changes in the present ... [more ▼]

The Antarctic surface mass balance (SMB, i.e. the snow accumulation from which we sub- tract ablation by sublimation, run-off or erosion) is a major yet poorly known contribution to changes in the present-day sea level. Water storage by snow accumulation at the top of the ice- sheet is expected to increase during the 21st century, which would moderate the rise in sea level. Three-quarters of the Antarctic SMB are concentrated below 2000 m above sea level whereas this area represents only 40% of the grounded ice sheet area. Orographic precipitation is a major contributor to snow accumulation in this region, which is why a better estimation of this term is important. The representation of this process by models depends to a great extent on the resolu- tion of the model, since precipitation amounts depend on the ice sheet slopes. Sublimation and snowmelt also depend on elevation. Global and regional atmospheric climate models are unable to achieve a 40-km resolution over Antarctica at a century time scale, due to their computing cost. At this resolution, ice-sheet margins are still badly resolved. <br />That is why we developed the downscaling model SMHiL (surface mass balance high-resolution downscaling), which estimates the Antarctic SMB components at a high resolution (∼15 km) from large-scale atmospheric forcings. We compute the impact of the high-resolution topography on orographic precipitation amounts and on the boundary-layer processes that lead to sublima- tion, melting and refreezing. To validate SMHiL, we compare our results with more than 2700 field data recently updated and quality-controlled. However, we exhibit that field data below 2000 m above sea level are too scarce to settle SMHiL efficiency. In light of this, we show that the GLACIOCLIM-SAMBA stake lines located on the ice sheet coast-to-plateau area is an ap- propriate reference to evaluate model performance. Finally, we downscale the atmospheric global climate model LMDZ4 to estimate the SMB changes during the 21st and 22nd centuries. The high-resolution SMB is significantly different from the SMB given by LMDZ4. Our results sug- gest that running LMDZ4 at a finer resolution may give a future increase in SMB in Antarctica between 15% to 30% higher than at its standard resolution. Future changes in the Antarctic SMB at low elevations will result from the conflict between higher snow accumulation and ru- noff. The downscaling model is a powerful tool that can be applied to climate models for a better assessment of a future rise in sea level. [less ▲]

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See detailEvolution du CA 125 et du SCC dans les cancers gynécologiques
Charlier, Corinne ULg; Plomteux, Guy ULg; Lambrichts, M.

in Focus Diagnostica (1992), 1

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See detailEvolution du champ de la Santé mentale en Belgique: de l’asile vers les réseaux et circuits de soins
Thunus, Sophie ULg; Cerfontaine, Gaëtan ULg; Schoenaers, Frédéric ULg

in Observatoire : Revue d'Action Sociale & Médico-Sociale (2012), 72

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See detailL'évolution du chlore inorganique au-dessus du Jungfraujoch et le Protocole de Montréal
Mahieu, Emmanuel ULg

Doctoral thesis (2001)

The main objective of this work was to determine the inorganic chlorine budget (Cly) at northern midlatitudes, to establish its variability and to study its temporal evolution over the last fifteen years ... [more ▼]

The main objective of this work was to determine the inorganic chlorine budget (Cly) at northern midlatitudes, to establish its variability and to study its temporal evolution over the last fifteen years. To achieve this, we have analyzed the observational database made of IR solar spectra recorded mainly with high resolution Fourier transform spectrometers installed at the International Scientific Station of the Jungfraujoch, located in the Swiss Alps, at 3580m altitude. The analysis of ATMOS (Atmospheric Trace Molecule Spectroscopy) data allowed us to first establish that HCl and ClONO2 account for more than 93% of the total inorganic chlorine, and that the summation of their vertical column abundances is an excellent surrogate of the Cly evolution at midlatitudes. Thus, we have derived HCl and ClONO2 total column abundance time series above the Jungfraujoch to analyze their temporal evolutions. Their combination has allowed us to show that the Cly increase between 1986 and 1995 (+50%) resulted primarily from the photodissociation of long-lived chlorinated source gas, in particular the manmade chlorofluorocarbons (CFC), progressively transported to the stratosphere after their release at the Earth surface during the seventies and the eighties. The organic chlorine (CCly) decrease in the troposphere resulting from regulations adopted by the Montreal Protocol, its Amendments and Adjustments, led to a progressive stabilization of Cly in the stratosphere. However, statistical analysis and interannual variability characterizing our time series, which extend to the end of 2000, prevent any final determination of the occurrence of the Cly maximum observed here at the end of October 1996, and of its subsequent decrease. We also show that chlorine partitioning among the chlorinated reservoirs has been durably influenced by heterogeneous processes which took place on stratospheric aerosols significantly enhanced following strong volcanic eruption of Mt Pinatubo (Philippines) in June 1991. The above-mentioned topics, complementary findings resulting from the study of the evolution of inorganic fluorine in the stratosphere, as well as comparisons other observational data bases and 2D model predictions are essentially discussed in Chapter 4. Before, Chapter 1 briefly reviews physical and chemical properties of the Earth atmosphere, and processes that control the state and erosion of stratospheric ozone. Individual contributions of chlorinated source gases to the CCly budget and their temporal evolution to the latter, inventory of Cly species, phase out schedule of chemical compounds covered by the Montreal Protocol and its Amendments and Adjustments are given in Chapter 2. Chapter 3 deals with instrumentation and data processing descriptions used to produce the geophysical data sets exploited in the main chapter of this work. [less ▲]

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See detailEvolution du Climat et Paléoclimat : effet de serre et CO2
Gérard, Jean-Claude ULg; François, Louis ULg

in Espace et environnement (1995)

Detailed reference viewed: 35 (4 ULg)